I was there, done that.
My biggest mistake was to trust the recommendations of fellow bikers for a LBS. They sold me a bike that did not fit well, was expensive and helped the LBS to clear the inventory. They closed shop 6 months later.
My recommendation is to study what you want and do not rely on any salesman.
More money for the bike should get you better functioning components like Shimano Ultegra or better yet Dura Ace.
Full Carbon Bikes ride smoother and are agile. My fellow bikers claim that Titanium is springy.
Bike fit is very critical. One inch makes a lot of difference.
I love my Trek Madone but I am sure that other bikes in that price range are very nice also.
One undesirable feature of the Madone is 25 mm max tires. The lousy roads around here would be better with 28 or 32 mm. I am using a Cycle Cross bike with 32 mm tires for that reason.
BTW, there are big savings if you accept last years model. You should be able to get a nice bike for $2,500 or less.